feat: absorb backends, ecs adapters, and gui plugins from labelle-cli - #7

Bugbot Analysis Progress (5m 41s elapsed)

✅ Gathered PR context (2s)
✅ Completed bug detection (5m 32s)
✅ Posted analysis results (8s)

Final Result: Bugbot completed review - no new issues found. 3 previously reported issues remain unresolved.

Request ID: serverGenReqId_fa40fe92-ebb5-477c-90b6-e23639910068